This is an indispensable resource to the sleep medicine clinician. focuses on the human aspects of sleep, integrating the various disciplines that are involved in sleep medicine like neurology, clinical neurophysiology, internal medicine (particularly pulmonology and cardiology), psychology, psychiatry, sleep technology, pediatrics, neurosurgery, otorhinolaryngology, and dentistry. working toward increasing worldwide awareness of the importance of sleep and the adverse consequences resulting from lack of sleep, due either to enforced lifestyle or to sleep disorders themselves. The aim is to act as a link between various sleep associations and cultures, i.e., as an international nexus among sleep clinicians and researchers in the advancement of worldwide sleep health. A special goal is to foster dissemination of expertise in sleep medicine everywhere in the world. The recent findings of decreased sleep spindle density (number of spindles per minute) correlating with impairment of both declarative and procedural memory in schizophrenia